Process of drying lumber



F. K. FISH, Jn. PROCESS OF DBYINGLUMBER. APPLICATION FILED sEPLzo.,I9I6. RENEWED IIov. 9. 1918.v

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F. K. FISH, Jn.

PROCESS 0F DRYING LUMBEH.

APPLICATION FILED sEPLzo, I9Ie. IIEIIEwED Nov. 9, 1918.

1 ,328, 505 Patented J an. 20, 1920.

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UMTED s'rATEs PATENT onirica.A

FREDERICK K. FISH, JR., 0F NEW YORK, N. Y., ASSIGNOR T0 LUMBER TIE ANDTIMBER VULCANIZING COMPANY, 0E NEW YORK, N. Y.

Pnocnss or nnYING LUMBEn.

To all whom t may concern.'

Be it known that I, FREDERICK K. FISH, Jr., a citizen of the UnitedStates, residing at 2 Stone street, New York city, in the county of NewYork and State of New York,

is closely allied to the cellulose of the wood,

and since it forms a part of the permanent 1ustructure of the wood, itmay, for purpose of the present invention, be regarded as identical withthe cellulose.

Of the other organic substances, the principal are starches, sugars,gummy substances, albuminous compounds and sap together with resin orresinous compounds mainly to be found in resin cells or ducts. Thestarches, sugars, stances with the sap are elements principallynecessary to the life of the growing tree but their presence in felledwood, timber or lumber, if in any quantity, is largely detrimental asaffording principal elements leading to the decay or destruction of thewood. .Therefore any proper treatment to preserve the wood should bedirected 'to the removal of injuriousstarches, soluble gums, albuminoussubstances and sap with the proper preservation and distribution of theresins and resinous substances throughout the structural elements, carelbeing taken to arrest the treatment and if a liquid is einployed toremove t e same from around the wood before disintegration of the woodbegins so that all` elasticity, strength and that which .is termed lifeare retained.

In carrying out my improved process, certain steps are provided toutilize the natural resins, acetic acid and tannic acid existing in thewoodfas preservative agents; that is to say, these constituents orsubstances are dislodged from their cellular confinement, and separatedfrom their original vehicle,

gums and albuminous sub-l Specification of Letters Patent. Patented Jan,20, 1920, Application filed Septemler 20, 1916, Serial No. 121,187.Renewed November 9, 1918. Serial No. 261,938.

Athe wood, and 'dissolves and dislodges the soluble ummy sap matters andsoftens the resins. his step causes the soluble mmy sap matters andthesap water to ecome intermingled with the vehicle in the container. Toobtain the desired results, the f period of treatment, the temperatureand the pressure, must be such as not to injure the wood. This step inYtheprocess also saturates and swells the wood, causing it to furtherexpandupon removal of pressure, and softens the resins and puts themA incondition to permeate the wood structure in a'subsequent-step or stepsin the process. This step in the process also puts the wood in goodphysica condition to give up its aqueons content in the subsequent stepsof the process.

In the next step, as the water and pressure are removed from around thewood, the differences between the internal pressure within the wood andthe external pressure surrounding it causes the wood and the liquidwithin the wood to further expand and considerable of the liquid withits dissolved constituents are removed from the wood in the form ofvapor and otherwise. Then a partial vacuum is created, the vacuum beingmaintained for a suiicient time to remove a portion of the aqueouscontent of the wood to be evaporated without taking with it the valuesof the sap, such for instance as the resin or the resin-producingconstituents. But' this vacuum should not be continued long enoughvtogreatly cool down the wood, allow its resins to harden, or close themoisture outlets of the wood at the surface. To

assist the withdrawal of the moisture from the wood the vacuum isreplaced with live steam, and a pressure created in and around the woodthereby raising the temperature of the wood, the last named vacuummaterially assisting the live steam to penetrate the wood structure.

Next, the wood is again subjected to a vacuum for a suitable period,which continues the drying of the wood.

Finally, the wood is subjected to what 1 term an equalizing step, whichconsists in maintaining around the wood an atmosphere of properhumidity, and a temperature sufficient to cause continuous evaporationof moisture, at the same time keeping the resins in a softened stateuntil the Wood is seasoned. 1t is in this step particularly thatpermeation of the Wood bers by the softened resins takes place. rlhewood thus described will be sterilized, tanned and dried, withoutremoving the insoluble resins, the fibrous structu`re of the wood beingpermeated with these resins. The wood is furthermore renderedsubstantially nonhygroscopic, and correspondingly immune from spores, orfermentation or the like, and undergoes the minimum amount of shrinkage.'llo illustrate one way of carrying out the process, reference is madeto the accompanying drawings wherein Figure 1 is a vertical longitudinalsection of a container, in which the Wood is partially treated. v

Fig. 2 is a cross section taken through the container.

Fig. 3 is a diagrammatic illustration of an apparatus for carryingoutthe steps of the process in the container.-

Fig=l 4 is a vertical sectional view of an equalizing chamber.

Fig. 5 is a cross section of the same on the line 5 5 of Fig. 4.

1n the drawings, the same reference characters designate like parts inall the figures.

1 indicates a container suitable for containing water under pressureat atemperature above the boiling point. 1n the container is a presser plate2, adjusted by screws 3, by means of which the wood, retained undermechanical pressure is pre vented from floating and warping while beingsubjected to treatment. The container is also provided with heatingcoils 4f, by

means of which the temperature of the at- Inosphere within the containerand the temperature and pressure of the water in the container may be yregulated. Perforated pipes 5, are arranged in the container forsupplying free steam to the latter, when des1re Suitable equipment isassociated with the container for conveniently developing the war-ionsconditions incident to the different steps in the process; 10 indicatinga pipe shown) and connected to the top of the container by a branch pipe9, and to the bottom of' the container by means of a branch pipe (5,provided with a valve 6a; and in the pipe 10a is a double acting pump11. Extending from the junction of the pipes 9 and 10, is a branch pipeS, provided with a valve 8C, leading to a condenser 8, and from thecondenser extends a short pipe connected to a vacuum pump 7. 1n thebottom of the container are rails to receive a truck, upon which theWood to` be treated is loaded.

Referring to Figs. 4 and 5, 13 indicates an equalizing chamberconstructed to have a high co-etlicient of heat insulation, and ispreferably provided with' a presser device 2, 3 similar to that employedin the container. The equalizing chamber is further provided withheating pipes 14, and a lower air inlet controlled by a suitabledamper16, and a stack or outlet, controlled by a damper 17. 1n thebottom of the equalizing chamber are tracks for convenient introductionof the truck with the charge of wood, previously treated in thecontainer.

1n practising the process, a charge of wood is loaded on a truck, andisintroduced into the container. the pressure .devices are screwed down,and the container is hermeti- `cally closed. c rlhe appropriate valvesare opened, and the vacuum pump 7, is operated, and a partial vacuumcreated in the container 1. This partial vacuum is maintained for asuitable time to expel air from the wood, and render the fibrousstructure more receptive to the penetration of the boiling water. This'step also preliminarily prepares the wood for the future treatments.

The valves are closed, and boiling water from the elevated tank isintroduced into the container through the pipes 9 and 10, the

,water being fed to the container by gravity,

or by pump 11. The vacuum in the container is broken by the introductionof the boiling Water.

Suiiicient water is introduced into the container to submerge the wood,and about twenty pounds pressure is produced and .maintained byintroducing steam through the heating coils 4r, which continues theboillng of the water and produces the necessary pressure and temperatureto superheat the Water.

lThis superheated Water step is maintained for a sufficient time todissolve the water soluble constituents of the wood, the superheatedwater being forced throughy the entire fibrous structure of the wood. For one inch yellow pine green from the saw about one hour is required.

By treating the wood'in superheated water the wood is rendered hot andsoft vthe internal stresses are relieved, the resins are softened andthe water soluble substarces are dissolved and with the sap water aremixed or intermingled with the water surrounding the wood. In addition"to these results, the superheated Water being confined causes adeposition of the colloidal substances on the fibers ofthe Wood, andtans the surface of the latter giving the Wood a distinctive appearance.

The Water introduced into the container, and in which the Wood issubmerged, re` mains as a relatively fixed body during the treatment,the valves being closed to prevent circulation, and the pressure devicespreventing thevwood floating or warping during this step in the process.

After the wood is subjected to the boilingstep, the valve (ia is"opened, and the pressure in the container will lforce the Water backinto the elevated tank, or the pump 11, maybe operated to effect thisresult.- The valve 6 is closed, and the' valve 8 is opened and thevacuum pump 7 is started and a partial vacuum of about 20 inches iscreated in the container, the change from liquid pressure to vacuumbeing effected as quickly as possible, say in about fifteen minutes. TheWood now has a high internal temperature and some pressure which willreadily convert Water into steam, making the Whole body of the woodfavorable to giving up moisture.

The vacuum may be malntained for a suiiicient time to cause the aqueouscontent of the wood to largely evaporate Without taking with it theresins or resin-producing constituents. But this eva oration should notbe continued long enoug togreatly cool down the Wood, or close its poresat the surface. Now to continue the evaporation of moisture from theinterior of the wood and prevent external drying, or danger of checking,the vacuum is gradually replaced by an artificial atmosphere of highvtempera'- ture, say about 290 degrees F. This condition is created byintroducing steam to theL container, through the perforatedv pipes 5,

the increase in temperature being 'assisted by circulating steam throughthe heating coils. Some pressure is maintained during this time-sayabout thirty pounds, and the step' is continued. for-say one-half hour,and has the effect of raising the temperature of the wood throughoutWell above the boiling point and keeping the retained resins in goodpermeating condition.

Next the steam is cut off from the perforated pipes 5 and the wood, athigh internal temperature and wlth softened fibrous structure, favorableto giving up -moisture, isl

This step is preferably continued for about two `hours, lbut the vacuummay be increased-say to abouttwenty-iveinchestoward the end of thestep-say for the last half hour thereof. This step in the process hasthe eiiect of aiding the uniform distribution of the resins throughoutthe wood structure, and when completed, the Wood is in condition to beremoved from the container.

The load of wood is now transferred as rapidly as possible, to theequalizing chamber 13, the load being preferably covered to minimizeloss of heat during the transfer. While the Wood is being treated in theequalizing chamber, another charge can be introduced to the container.

It is important in carrying out the final step of the process that thetemperature and humidity be such as to prevent premature hardening ofthe resins of the wood, and insure continuous evaporation of moisture,

without checking or otherwise deteriorating the value of the Wood. -Itis to be borne in mind that the internal temperature of the Wood whenintroduced into the equalizing chamber is high, and that it containsmoisture, and the resins are in. a softened state. It is here, andwhile'the resins are in this condition that permeation of the celluloseby resins and such of the ummy substances remaining in the Wood ta esplace.

Steam is admitted to the heatin pipes 14, to maintain a temperaturefavora le to continuous evaporation of moisture from the wood, and thedampers 1G and 17 are opened periodically to create a current orcurrents of air to the chamber for periodically carryving off themoisture as it accumulates. This step evaporates moisture from the woodand equalizes its moisture content and insures the permeation of theindividual fibers of the wood with its resins.

Inthe treatment and drying of wood, I have had in mind the fact that itis essential that the resins must be retained and yet the major portionof the water solublecon-v stituents and the water sap closely associatedment, should as far as possible, as a preliminary step, be removed.`Hence, when the Wood is placed in the sealed container and the firstvacuum is created, alarge portion of the air throughout the body of thewood is ex lled, and while the Wood is in this condition boiling wateris introduced to 'at least submerge the wood. Then p ressure is createdAin the container by operating the pump and the tempe ature of the wateris raised by introducing steam through the coils Je, the addedtemperature and consequent pressure causing the Water to be superheated,and in this condition it is forced into the Wood. rlhe change fromvacuum to pressure takes place to insure as perfect penetration of theyvood as possible, the con# dition of change from vacuum to pressureheilig controlled by the proper manipulation of the valves. The yvoodis, by this means, and Without loss of time. put into good condition forthe effective penetration of the water. to readily attack the yvatersoluble constituentsl throughout the whole Wood structure. The vacuumhaving been broken or destroyed, and the Isuperheated Water having beensubstituted. the wood is treated until it is rendered hot and soft andwill become enlarged upon release of thepressure surrounding it. The`Water soluble constituents are dislodged from their cellularconlinement. and dissolved in the Water in the wood, and because of theboiling action under pressure these dissolved ingredients are conveyedor removed from the interior of the Wood ,and become mixed orintermingled with the confined body of water in the container. The waterand heat. together with the pressure which forces the Water int'o theWood. acts to dissolve the gummy sap matters, but in so doing care mustbe taken to regulate the temperature and pressure and duration oftreatment to prevent disintegration or destruction of the Wood.'

Stress is put on the fact-that treating the Wood for a short time underlow h eat and corresponding pressure to soften the resins and expelyvater soluble constituents. 1s to be distinguished from what is knownin the art as cooking the life from the wood.

T he superheated water. chai'ged with the water soluble kgums and sapwater, is removed from the container by manipulation of the propervalves, and returned to the elevated tank for re-use. The wood now' ishot and soft, the internal stresses having been relieved, 'its pores areopened up, and its contained resins are in a softened state. Therefore.the succeeding steps in the process have to do largely with theevaporation of the moisture in the wood structure, the maintaining ofthe resins in good condition to permeate the fibers, and the thoroughpermeation of the fibers with the resins. without liability to producechecking of the wood.

The Water having been removed, a second vacuum is now createdtoevaporate the moisture content of the wood and permit penetration ofsteam introduced in a further step. rlhe second mentioned vacuum 1sgradually replaced hy artificial atmosphere of high pressure and highltemperature to raise the internal heat in the wood well above, theboiling point. This step insures the retained resins in the woodremaining in a softened condition, to later enable them' to permeate theindividual bers of the Wood in a subsequent step or steps in theprocess.

After this step of the treatment, the Wood is lsubjected to the actionof the third vacuum with dry heat which acts to cause the softenedresins to be uniformly1 distributed throughout the wood structure.

It is essential however that the Wood be further treated to complete itsdryingwithout. hardening its resins and vchecking or otherwise degradingit. Therefore, I provide the next or equalizing step in the process.After the last mentioned, or third vacuum is broken. the load of wood isremoved to the equalizing chamber Where it is permitted to remain untilsufficient moisture evaporates. The yvood at this time contains highinternal heat'` and the chamber is pro-- vided with means to maintain atemperature effective to sustain a moderated and continuous evaporationof the moisture in the Wood and to maintain the resins in a meltedcondition in the Wood until the wood is finally dried and cooled.

Upon the first introduction of the Wood in the chamber the dampers 16and 17 are closed and the e 'aporated moisture rapidly creates a humidcondition within the cha1n ber. As the humidity increases, a depositionof moisture occurs on the surface of the ivood, and as the point ofsaturationis appreached evaporation of the moisture ceases. At such timethe dampersare operated to relieve the condition within the chamber, andthis may be secured either by opening the upper damper alone, or byperiodically opening` both dampers. If the upper damper-alone is openedit causes a lowering of the slightly. raised pressure within thechamber, the excess moisture around the vvoodv 1being removed from -theequalizing chamber. As the pressure Within the cham: ber is so loweredthe high heatand consequent pressure within the interior of the Woodproduces vaporization of the interiorly contained moisture and suchpressure withinV thevwood causes a movement of the moisture surfacewise.whereby a too rapid surface drying is avoided and in` addition anincreased rapidity of drying of the Wood as a Whole is secured.

If the lowerdamper is opened simultaneously or periodically with theupper damper open, a currentof air is caused to circulate throughout thechamber to accelerate the evaporation of the moisture.

As the moisture content evaporates from the wood fibers, the resinsbeing in a softened condition spread, and replace this evaporated,moisture the resins permeati'ng the wood structure and flowing aboutand into the wood fibers in such manner that upon cooling the settingresins aid to maintain the wood fibers in their expanded con-"' ditionso that when finally dried the Wood shows the minimum degree ofshrinkage.

wood in previous treatments forms a diluted solution, and when treatingthe next load of green Wood, the contained substances act to tan theWood, theV effect and res-ult depending largely on the character of Woodand the number of times the Water is used.

What I claim is l 1. The process of treating Wood comprismg subjectingthe Wood to superheated watei` until its Water soluble constituents aredissolved and with its sap Water largely removed and the Wood thoroughlysterilized throughout, and arrestin the treatment before anydeterioration if the Wood occurs, to produce a Wood resistant to decayand jvith its strength and elastic'properties urnlmpaired.

2./The hereindescribed process of treating Wood comprising thesubjection of the wood to heated Water under pressure to dissolve itsWater soluble matter While held submerged and to prevent warping,remoring the Water and releasing the Wood, and subsequently drying theWood.

3. The herein described process which comprises dissolving in Woodsubstantially all Water soluble constituents and removing the majorportion of the same, then drying the wood at a temperature suicient tocause evaporation of the moisture in the wood, prevent hardening of itsresins and cause permeation .of the fibers with the residue and theresins.

4. The process of treating' Wood comprising4 applying boiling water towood, submerging the Wood therewith, and` thereafter superheating theWater to raiseits tempera- .ture and pressure to cause same to permeatethe Wood throughout, and arresting the treatment before deteriorationofthe Wood occurs. v

5. The'proccss of treating Wood comprising submerging wood in a confinedbody of superheated Water to dissolve and extract the soluble gums andsap, and subsequently subjecting the wood to a temperature to induceevaporation of the moisture of the wood and prevent hardening of theresins, causing the resins to permeate the fibers of the wood.

, 6. A process of treatin wood comprising' treating the Wood to disso veand remove its sap matters, subjecting the .wood to alter- A nate vacuumand pressure treatments and maintaining a temperature the Woodsufficient to cause the molsture 1n the wood to evaporate and preventhardenmg 'of the quently permeation of the Wood throughout and to i'dissolve substantially all constituents which may be dissolved in Waterand removing the major portion of these constituents with the water, anddrying the wood.

8. The process of treatin Y, wood comprising submerging the wood 1n afixed body of water under pressure and with heat to extractWater-soluble constituents and sap Water from the Wood and melt theresins therein, removing the Water, and subsequently subjecting the Woodto a temperature sufficient to induce' evaporation of the moisture inthe Wood and prevent hardening of the resins and vcause the resins topermeate the individual fibers ofthe wood.

9. The process of, treating wood comprising submerging the wood in watercontaining the water soluble constituents of Wood under pressure tosaturate the same, dissolve and extract the major portion of the Watersoluble constituents and subsedrying the Wood.

l0. he process of treating Wood by subjecting it to a deposition oftanning col. lodial substances on the' surface portions of the Woodthereby tanning the same While removing the major portion of the Watersoluble constituents.

lmajor portion of the water soluble constituents and sap Watertherefrom, and expand the fibers thereof, then drying the wood to removethe major portion of the moisture in the Wood, the tanning colloidsremoved from the wood and retained in the water being deposited-on thefibers of the Wood to thereby tan the same.

12. The process of treating and drying wood, comprising subjecting thewood to steam and heat, to maintain the steam and raise the temperaturethroughout the wood, then to a vacuum to cause a movement of theinterior moisture surface-wise to evaporate moisture therefrom, andfinishing the drying at atmospheric pressure.

13. The process of treating wood comprising applying boiling Water towood, which has been previously employed 'in a similar treatment ofWood, then submerging thel wood therewith and thereafter superheatingthe Water to raise its temperature and ressure to cause same to permeatethe woo throughout.

14.- The process of treating wood which comprises surrounding the woodwith heated water which has beenV previously similarly melted condition,comprising subjecting the Wood to a temperature to induce evaporation ofthe moisture in the Wood, prevent hardening of the resins and to causethe latter to permeate the fibers of the Wood.

16. The process of drying Wood having soluble gums and sap Water removedand its resins in a softened condition. consisting in subjecting thewood to heat sufficient to induce evaporation of the moisture in the\vood and prevent hardenmg of the resms, causing the resins to permeatethe fibers of the wood,

and periodically subjecting the wood to a current. of air to carry offthe moisture as it accumulates around the wood, at the time. the wood issubjected to the heat.

1T. The process of drying wood having a portion of its gummy sap matterand sap 4water removed and lts resin softened, consisting in subjectingthe wood Ito alternate vacuum and pressure and maintaining suiieientheat to prevent hardening of the resins, and then removing the moisturesurrounding the wood by periodically subjecting the wood tov acurrent ofair to produce a substantially sterilized Wood, having its preservativeelements retained and distributed throughout the struc-ture.

18.. The process of treating wood comprising treating the wood withwater to dissolve, dilute and remove the major portion of its watersoluble constituents, and cause the thorough permeation of the wood Withthe unremoved remaining preservative elements and drying the Wood.

19. The process of treating wood comprising subjecting the Wood totreatment to remove the major portion of the soluble gums and sap matterand thereafter treating the Wood to evapo 'ate moisture and cause theretained resins to spread throughout the wood to substantially replacethe soluble gums and sap matter.

20. The process of treating wood, com-A prising placing the wood in acontainer. creating a vacuum therein, submerging the wood in boilingwater, withdrawing the water, then creating a vacuum in said containerwhile supplying heat therein 'to evaporate moisture and create expansionin the wood.

21 The process of treating wood, comprising treating the wood insuperheatedwater. to soften its structure and dissolve water solubleconstitutents, subsequently Withsoften its fibers and dissolve the Watersoluble constituents and finally drying the Wood while maintaining heatsuiicient to induce evaporation and prevent hardening of the resins.

23. The process of treating wood comprising subjecting the wood to avacuum toeX- pel a. portion of the air therefrom, then treating the Woodin superheated Water to permeate the same to dissolve and remove itswater soluble constituents, and arresting the treatment beforedeterioration of the wood occurs.

24. The process of treating wood comprising subjecting the Wood tosuperheated water until its struc-ture is softened and Water solubleconstituents are dissolved, removing the vater from around the wood,then subjecting the Wood to a vacuum to evaporate moisture and causeexpansion in the Wood, drying the, wood While maintaining heatsufficient to induce evaporation and prevent hardening of the resins topermit them to replace the removed substances.

25. The process of treating Wood Which comprises subjecting wood to theaction of super-heated water for a period of time to melt the resins ofthe Wood and dissolve its water soluble constituents, then removing thewater and subjecting the wood to heat sufficient to cause evaporation ofthe Water in the wood and prevent hardening of the resins of the. woodand insure a permeation of the fibrous structure .of the wood by itsresins. f

Q6. rlie process of treating Wood comprising subjecting the wood tosuperheated water until its structuri is thoroughly softened and itswater soluble constituents are dissolved, removing the water. thensubjecting the wood to a vacuum until a portion of its moisture iswithdrawn and expansion is created in the wood. then subjecting the Woodto steam to raise the temperature of the Wood and evaporate a vportionof its moisture.

27. The process of treating wood comprising the subjection of the Woodto superheated water until its soluble constituentsl and sap matter aredissolved and largely removed and the wood thoroughly sterilizedthroughout, arresting the treatment before any sul'istantialdeterioration of the wood occurs. removing thefivater and subjecting thewood to steam under pressure to raise the temperature and evaporate aportion of -in'g subjecting the Wood' to superheated Wathe moisture, andfinally subjecting the wood to heat sufficient -to induce evaporationand preventing hardening of the resins. n 28. The )rocess of treatingwood comprising the su jection of the Wood to super-, heated water untilits soluble constituents]v and sap matters are dissolved andlargelyremoved and the Wood thoroughly sterilized' throughout, arresting4the treatment before any. substantial deterioration of the wood occurs,removing the water, and subjecting the' wood to steam: to raise thetemperature and evaporate a4 portion ot its moisture.

29. The process of treating wood compris-v ing subjecting the wood tosuperheated iva-v ter until its structure is thoroughly softened jsure,to raise the temperature ot' the wood andevaporate a portion of itsmoisture, then creating a vacuum While applying heatto further evaporatemoisture, then drying thel'wood While maintaining heat suflicient Atoinduce evaporation and prevent hardening of thefres'il.- Q Y Y 30. Theprocess' of 'treating wood compris-V ter until itsstructure isthoroughlysoftened vand its water soluble constituents are dissolved, removing thewater, then subjecting the Wood to a vacuum until a portion of itsmoisture is withdrawn, then subjecting the Wood to 4steam to raise thetemperature of the wood and evaporate a portion of its moisture, thencreating a vacuum while applying heat to further evaporate moisture. 31.The process of treating Wood, coinpiising subjecting the wood to -avacuum, then submerging the ivood in boiling water and raising thepressure thereof and treating the wood in superheated water, removingthe Water and substituting therefor a vacuum; then subjecting the woodto steam While creating a high temperature around the Wood, finallydrying 'the wood at about atmospheric. pressure and in the presence ofheat u'hile periodic-ally removing the accumulat-ing moisture -from theatmosphere surrounding the Wood.

32. The process of treating wood comprising subject-ing u'ood to avacuum, to expel a. portion ot' the air therefrom. treating lthe wood tosuperheate-d water to soften its structure and dissolve the Watersoluble constituents, removing the water, then subjecting the wood to avacuum to evaporate the moisture from the wood, and inally treating theWood with steam to induceevaporation j and prevent hardening of theresins.

33. The process of treating wood comprising subjecting the wood tosuperheated water until its structure is thoroughly softened and itswater soluble constituents are dissolved, removing the Water. subjectingthe Wood to steam under pressure to raise the temperature of the Woodand evaporate a portion of its moisture, then creating a vacuum toevaporate moisture and cause expansion in the wood, then drying theivood while maintaining hea-tsuiiieient to induce evaporation andprevent Vhardening ot' the sa. The'l ter and thereafter superlieatingthe ivater, then 'removingl the water and substituting therefor avacuum; then replacing this vacuum bysteam then replacing the steam witha vacuum; and finally finishing the drying at about atmospheric pressureand in the presence of heat\vhile periodically removing the accumulatingmoisture from the atmosphere surroundingtlie wood.

Y 35. The process of treating Wood, comprising subjecting the wood toboiling water to soften its structure, open up its pores and dissolveits sap; then subjecting the Wood to successive. vacuum treatments withan iiitervening raising of the pressure around the Wood; the temperatureof the wood duringv these steps being maintained sufficient toinduceevaporation and prevent hardening of the resins, the wood being finallydried at about atmospheric pressure. t

'96. The process of treating Wood, coniprising boiling the ivood tosoften its structure, open up its pores and dissolve its sap; thensubjecting the wood to a. plurality of vacuum treatments alternated withsteam, the temj'ieraturc of the wood during these steps being maintainedsufficient. to induce evaporation and prevent hardening ot the resins;the wood being finally dried by heat at about atmospheric pressure, thetemperature being lnaintained sufficient 'to prevent hardening ot the.resins and permeate the fibers ofthe wood with its resins.

37. The process of treating wood, comprising subjecting the Wood to avacuum, then replacing the vacuum by boiling Water and raising thepressure above atmospheric, removing the water, and treating the woodwith steam under pressuregthen creating a vacuum; and linishing thedriving at about atmospheric pressure with heat while periodic-allyremoving the accumulating moisture surrounding the Wood'.

3S. The process of treating Wood, coinprising subjecting the Wood to avacuum and iinlnediately thereafter boiling it in Water until itsstructure becomes soft, its pores are opened and its guminy sap mattersare dissolved; then vwithdrawing the Water and subprocess ottreatingu'ood, com-V prising subjecting the wood to a vacuum; thenreplac'ing thevacuum with boiling iva.-

jecting the Wood to steam and heat and'raising the pressure surroundingit; 'then subjecting it to a vacuum,-`mally drying the Wood at aboutatmospheric pressure.

39. rlhe process of treating Wood, comprising placing the wood in acontainer, surrounding the Wood with boiling Water until its pores areopened up, its structure thorremoving the Water, treating the Wood tosteam under pressure to increase the internal heat of the Wood andevaporate a portion of the moisture, then subjecting the wood to avacuum while applying heat to evaporate moisture and cause expansion inthe wood.

41. The process of treating Wood, comprising boiling the Wood to softenits structure, open up 1ts pores, and dissolve its sap, then subjectingthe Wood to aplurality' of vacuum treatments alternated With steam, thetemperature of the wood during these steps being maintained up to adegree suilicient to induce evaporation and prevent hardening of theresins and drying 'while periodically removing accumulating moisturesurrounding the woodl 4t2. The process of treating Wood comprisingsubmerging the Wood in heated Water to dissolve and remove soluble gumsand sap, removing the Water, and subjecting wood to steam under pressureand simultaneously introducing dry heat to maintain the temperature ofthe steam to evaporate the moisture in the wood.

43. The process of treating Wood, comprising subjecting the wood toheated water uny der pressure until the pores of the Wood are" openedup, its structure thoroughly softened and "its gummy Vsap matterdissolved, and largely removed, removing the Water; subsequentlysubjecting the wood to a'vacuum while applying heat to evaporatemoisture. j

44. The process of treating wood, comprising boiling the Wood to softenits structure,' open up itspores and dissolve its sap, then subjectingthe Wood to heat and steam under pressure; the wood being finally dried.

' at a temperature suliicient to'cause evaporation of the moisture fromthe Wood and prevent hardening of the resins and cause,

permeation of the wood fibers with its'resins.

' 45. The process of treating Woodcompris- A ing subjecting the wood' toboiling water until its structure is thoroughly softened and 'watersoluble' constituents are dissolved and removed, removing the Water,treating the Wood with steamunder pressure to increase the internalheat` of the Wood, and evaporate a portion of the moisture and thendrying the Wood.

46. The process of treating Wood, comprising boiling the Wood to softenits structure, open up its pores and dissolve its sap; then subjectingthe Wood to a plurality of vacuum treatments alternated with a raisingof the pressure around the wood; the temperatureof the Wood during thesesteps being maintained up to a degree sufficient to induce evaporationand prevent hardening of the resins and cause a permeation of the bersof the Wood by its resins.

4J?. rlhe process of treating Wood, comprising boiling the Wood tosoften its structure, open up its pores and dissolve its sap; thensubjecting the Wood to a plurality of v2 enum treatments alternated withlive steam, the

last of said vacuum treatments being varied in. its intensity; thetemperature of the Wood during these steps being maintained up toadegree suliicient to induce evaporation and preventhardening of theresins; the wood being finally dried at about atmospheric pressure.

48. The process of treating Wood comprising subjecting wood to a vacuumto expel a portion of the air therefrom, treating the Wood 'with steam,then a vacuum to evaporate moisture, and then subjecting. the Wood toheat at about atmospheric pressure While periodically removing theaccumulating moisture surrounding the Wood.

49.' The process of treating Wood comprising thewood to steam, toincrease its internal temperature and evaporate moisture, then to avacuum to evaporate moisture from .the Wood and expand the Wood andtlien'subjecting the wood to heat While peing subjecting the Wood to avacuum, treatriodically removing the accumulating moisture andsubjecting the Wood to a vcurrent Oifair- Y .50. The process of treatingwood comprisingsubmerging the Wood in 'su erlieated water to dissolveand remove solulble gums and sap, removing the Water, subsequentlydrying the Wood in a moderately heated atinosphere with moisturesufl'icient to prevent Y too superficial 51. The process of treating-Wood comprising subjecting thewood to a vacuum to expel a portion oftheair therefrom, treating the Wood with steam and heat to increaseitsinternal temperature and evaporate moisture therefrom, finally dryingthe Wood at about atmospheric pressure to induce evaporation. 452. Theprocess of treatingiwood, comprising subjecting .the Wood vto a vacuum,and thereafter boiling it until its structure becomes soft, its poresare opened and its Lemmer gunnny sap matters are dissolved; thensubjecting the Wood to a plurality of vacuum treatments alternated witha treatment 0f steaii under pressure, and finally drying the woo 53. Theprocess of treating Wood comprising subjecting the wood to a' vacuum toexpel a portion of the air therefrom, treating the wood with steam and`heat to increase its internal temperature, then to 'a vacuum toevaporate moisture froml the wood, then subjecting the Woodto heat atabout atmospheric pressure. sufficient toevaporate moisture therefromwhile peri-A odically removing moisturefrom the wood.

54. The process of treating wood,`com prising subjecting the wood tovacuum and thereafter boiling it until its structure becomes soft, itspores are opened and its gummy sap matters are dissolved; thensubjecting the wood to a vacuum; then, while maintaining the internalheat of the wood, raising the pressure surrounding it; then subjectingit to vacuum and finally drying the wood at about atmospheric 4pressurewhile periodically removing the accumulating moisture surrounding thewood. i

55. The process of treatin prising subjecting the Wood to the action'ofa vacuum to remove the air therefrom, then submerging the wood in waterVunder pressure todissolve and extract the soluble gums andsap water,arresting the treatment, and

subsequently drying the wood.

56. The process .of treating wood, com'- prising subjecting the wood toa vacuum and thereafter to heated water until its structure becomessoft, its pores are opened and its mmy sap matters are dissolved; thensub ecting the wood to vacuum; then, while maintainingv the internalheat of the wood, raising the pressure rsurrounding it; subsequentlysubjecting it. to lvacuum and inally drying the wood at aboutatmospheric pressure. o

57. The process of treating wood, coinprising submerging the wood inwater under pressure and heatlng the water to dissolve and extract thesoluble gums and sap and meltv the resins, removing the water andsubsequently subjecting the wood 'to a temperaturefsucient to induce'evaporation of the moisture in the wood and prevent hardening of theresins, thereby causing the resins to permeate the fibers of the wood.

58. The process of treating wood which comprises placing wood in acontainer submerglng said wood in water previously used in a similartreatment of Wood to dissolveand remove Water soluble constituents, andby pressure forcing the water into said wood to uniformly permeate thefibers and dilute the sap, withdrawing the water from the wood, andsubjecting the wood to treatment to evaporate the moisture in the wood.

wood comv `59.'The process of treating wood, comprising subjecting thewood to heated water under pressure until its structure is thoroughlysoftened and its sap matters are dissolved; then subjecting it to avacuum until a portion of its moisture is withdrawn; .then subjecting itto steam under pressure; then subjecting it to a vacuum of increasingintensity while applying heat.

60.*The rocess of treating wood, comprising subjecting the wood toheated water under pressure until its pores are opened and its gummy sapmatters dissolved, subsequently 'subjecting the wood to a vacuum toevaporate moisture and cause expansion in the wood and subsequentlysurrounding the wood with 'a body of dryin heat suficient to prevent thehardening o the resins of the wood.

61. The process of treating wood, comprising submerging the wood in`water at a temperature and at a pressure suiiicient to open its poresandv dissolve its gummy sap matters, then creating a vacuum around thewood to evaporate moisture and create expansion in the wood, and finallysubjectingL the water and subsequently subjecting the wood to steamunder pressure and applying heat; then subjecting the wood to a vacuum,

and finally drying the wood at or about atmospheric pressure.

63. The process of treating wood, comprising` subjecting the wood toheated water under pressure to soften its structure, open up its poresand dissolve its. water soluble constituents; subsequently subjectingthe wood to steam under ressure: the temperature 'of the wood' beingmaintained up to a-degree suiicient to induce evaporation and preventhardening of the resins.

64. The process of treating wood, comprising immersing the Wood in Waterunder pressure until the wood is softened, the pores opened up and theWater soluble con- `vstitutents dissolved, then applying heat suficientto evaporate the moisture from the wood, and periodically removing theaccumulating moisture from around the wood and intermittently passing acurrent of air over the wood. t

65. The process of `treating wood, comprising subjecting the wood toheated water to soften its structure, open up its pores and dissolve itssaps; then subjecting the wood to a plurality of vacuum' treatmentsalternated with a raising of the pressure aroundv the wood; thetemperature of the wood during these steps being maintained up to adegree sufficient to induce ready evaporation and prevent hardening ofthe resins. I

66. The process of treating wood which comprises placing wood in acontainer, submerging said wood in water and by pressure suflicient toforce the water into said wood to permeate its fibers and to dissolveand remove the water soluble constituents, withdrawing the water, andsubjecting the wood to treatment to evaporate the moisture.

67. The process of treating wood `comprising submerging wood in heatedWater under pressure, then subjecting the wood to the action of avacuum, and subjecting the wood to heat at a temperature to induceevaporation of moisture of the wood and prevent hardening of the resinsthereby causing the resins to permeate the individual fibers of thewood. i

68. The process of treating wood, which comprises placing wood -in acontainer submerging said wood in a Xed body of water and by pressureforcing the water into said. wood to permeate the wood fibers and dilutethe sap of the wood, withdrawing the water from the wood, and subjectingthe wood to heat to evaporate the moisture in the wood,

and cause the resins to permeate the fibers. i

69. The herein described process of treating wood comprising thesubjection of the wood to a vacuum to withdraw air from the wood, thensubjecting the wood to heated water to dissolve its water solublesubstances.

and open up its pores and expand the wood, removing the wat-er, againsubjecting the Wood to a vacuum to evaporate moisture, from the wood,the wood being held in fixed position to prevent warping while beingsubjected to treatment, and subsequently dr ing the wood.

0. The process of treating wood, comprising boiling the wood to softenitsstruci ture, open up its pores and dissolve and remove Watersolubleiconstituents, and then subjecting the wood to heat and steamunder pressure to evaporate moisture from the wood. Y

71. The process of treating woodl comprising boiling the wood to softenits structure, open up its pores and dissolve and remove Water solubleconstituents, then subjecting the wood to a vacuum, thereafter treatingthe wood to steam under pressure, and then treating the woodto a vacuumto evaporate moisture.

72. The process of treating wood, comprising subjecting the wood toboiling water to soften its structure, open up its pores and dissolveand remove water soluble constitu-- ents, then subjecting the wood to avacuum, and thereafter treating the wood to steam under pressure toevaporate the moisture.

73. The process of treating wood, comprising subjecting the wood toboiling water to soften its structure, open up its pores and dissolveand remove water soluble constituents and thereafter subjecting the woodto a vacuum and to heatjto evaporate moisture from the wood and preventhardening of the resins.

74. The process of treating/wood comprising subjecting the wood to avacuum to expel air therefrom, then subjecting the wood to boiling Waterto dissolvethe water soluble constituents, then to avacuum, thereaftersubjecting the woodto steam under pressure, and then dryingv the wood atabout atmospheric pressure while periodically removing accumulatingmoisture from the atmosphere surrounding the Wood.

T5. The process of treating wood comprising subjecting the Wood to avacuum to expel air therefrom, then subjecting the wood to boilingwaterto dissolve 4and remove water soluble constituents, then to a vacuum,then subjecting the Wood to steam under pressure to evaporate themoisture. 76. The process of treating wood comprising treating the woodin boiling water, applying pressure to the boiling water to force thelatter into the wood to dissolve and remove the major portion of watersoluble constituents, arresting the treatment before removal of thepreservative elements, and then applying heat to dry the wood.

77. The process of treating wood comprising subjecting the wood toboiling water to open the pores and dissolve and remove the majorportion of the water soluble constituents, and then drying the wood atabout atmospheric pressure While periodically removing accumulatingInoisture from the atmosphere surrounding the wood.

78. The process of treating wood comprising boiling the wood to open itspores and dissolve and remove the major portion of the water solubleconstituents, and melt and diffuse the contained resins, thereafterdrying the wood at a temperature to cause evaporation 'of moisture fromthe wood,

prevent hardening ofthe resins and cause permeation of the fibers of thewood by its resins.

79. The process of treating wood com--` prising boilin the wood, to openits pore-.a and. dissolve'tie sap, thereafter subjecting the wood tosteam under pressure, then to the action of a vacuum, `and then dryingthe Wood at a temperature to cause evaporation of moisture from thewood, prevent hardening of the resins and cause permeation of the fibersof the Wood by its resins.

80. The process of treating Wood comprising boiling the wood to openitsv pores and dissolve the sap, then subjecting the wood to a vacuum,then to steam under pressure, then to a vacuum, and thereaftersubjecting the Wood to a temperature sulficient to evaporate moisturefrom the Wood and permeate the fibers with its resins.

81. The process of drying Wood comprising subjecting the Wood to heatsufficient to evaporate the moisture, and periodically removing theaccumulating moisture from around the Wood and intermittently passing acurrent of air over the Wood to cause uniform evaporation.

82. The process of treating and drying wood comprising heating the Woodto cause evaporation ofthe moisture from the Wood While preventing theremoval of the moisture from the drying chamber to create around theWood a humid condition above saturation, then relieving the humidity andperiodically passing a current of air around the Wood, the internaltemperature of the Wood being maintained at a temperature sufficient tovaporize the interior moisture of the wood.

83. The process of treating and drying Wood comprising heating the Woodto cause evaporation of the moisture from the Wood While preventing theremoval of the moisture from the drying chamber to create around thewood, a humid condition above saturation, then relieving the humidityand passing a current of air around the Wood,

the internal temperature of the Wood beingV maintained at a temperaturesufficient to vaporize the interior moisture of the Wood.

84. The process of drying wood comprising subjecting the Wood to atemperature in a substantially xed air until the humidity i approachessaturation to Ja deposition of moisture on the surface of the Wood, and

then relieving the humidity to evaporatey such moisture, the interior ofthe Wood being maintained at a temperature suiicient to vaporize theinterior moisture.v

85. The process of treating Wood comprising subjecting the Wood to steamunder pressure and to temperature for sufiicient time to melt itsresins, dilute its'sap and raise the interior temperature of the Wood,then to a vacuum to remove vapor therefrom, and then to heat and aboutatmospheric pressure, While periodically subjecting the wood to acurrent of air.

86. The process of treating and ldrying Wood comprising subjecting Woodto steam While maintaining heat to `raise the temperature throughout theWood and evaporate vapor therefrom, then to a vacuum to cause moistureand sap to move towardLthe surface of the Wood and to remove moisturetherefrom, and then subjecting the Wood to heat at about atmosphericpressure sutlieient to cause evaporation While periodically removingaccumulating moisture from the atmosphere surrounding the Wood.

S7. The process of drying and treating .vood comprising forcing Waterinto the wood to dissolve and remove the major portion of the Watersoluble constituents, the water being heated to raise the vinteriortemperature of the Wood, arresting the treatment before deterioration ofthe wood occurs, and thereafter subjecting the Wood to heat to dry itWithout degrading it.

SSQThe process of treating wood comprising subjecting the wood toalternating vacuum and Water treatment under pressure, said Water beingat a temperature above the boiling point, and thereafter drying theWood.

89. The process of treating Wood comprising subjecting'the Wood to steamunder pressure, and to temperature for sufficient time to melt itsresins, dilute its sap and aise the interior temperature of the Wood,then to a vacuum to remove vapor therefrom, and then to heat and aboutatmospheric pressure While subjecting the Wood to a current of air.

90. The process of treating wood comprising subjecting the Wood to steamunder pressure, and to temperature for suiicient time to melt itsresins, dilute its sap and raise the interior temperature of the Wood,then to a vacuum to remove vapor therefrom, and then to heat and aboutatmospheric pressure While subjecting the Wood to a current of air tocomplete the drying.

91. The process of treating Wood comprising subjecting the Wood to steamunder pressure and to temperature for suflicient time to `melt itsresins, dilute its sap and raise the interior temperature of the Wood,then to a vacuum torcause the moisture in the Wood to move surface-wise.

92. The process of treating Wood comprising subjecting the' Wood to avacuum, thereafter treating the Wood to steam under pressure and totemperature for sufficient time to melt its resins dilute its sap andreinove moisture, then to a vacuum to remove vapor, therefrom, and thento a current of air.

In testimony whereof I aix my signature.

